The Interns' Guide: Where to Go if You're Under 21

Coffeehouses are a traditional choice, and the Dupont Circle branch of Cosi, Arlington's Murky Coffee, Old Town Alexandria's Misha's and Silver Spring's Mayorga are excellent and offer plenty of opportunities for people watching.

If you simply must join friends at one of those hot lounges or restaurant bars, the best suggestion is to visit on a weeknight, when most don't post a leather-jacketed colossus at the door to check IDs.

On weekends, one good idea is the Black Cat's Red Room, which features an excellent jukebox stocked with rock, soul and jazz, a pool table, pinball machines and several large booths. You can order from the Food for Thought Cafe on the other side of the club, and there's always an optional DJ night (ranging from free to $6) on the backstage. The downside: It's loud, smoky and packed on weekends.

If you're interested in shooting pool, Buffalo Billiards and Ballston's Carpool allow anyone to play until 6 p.m. on Saturdays and Sundays. (After than and during the week, though, it's 21-and-over only.)

18-and-over Club Nights

There are plenty of mainstream clubs that open their doors to under-21s on certain nights. Below are the clubs that let everyone in to dance. Unless otherwise noted, all events listed are 18-and-over, and IDs are required.

Thursday
Alchemy -- This night for the goth and industrial music scenes often features well-known live acts on Nation's large stage. When there's no band, however, admission is two-for-one between 9 and 10.

College Night -- It's College Night every Thursday at Apex, a staple of the Dupont gay circuit. DJ Timothy Mykael spins dance music from house to trance. Anyone with a college ID gets free admission; it's $5 for everyone else. Doors open at 9.

College Thursdays -- Although the swank Platinum club calls it College Thursdays, the dance floor is often full of people who've already matriculated. DJs spin hip-hop on the main floor and house and Latin in the VIP room. Get free admission before 11 with a college ID. Doors open at 10; and while jeans are allowed, athletic apparel isn't.

Destiny -- The vast Fur nightclub -- formerly a warehouse that stored fur coats -- features reggaeton, bachata, salsa and Latin music pumping out of the huge speakers on the main dance floor, with hip-hop and reggae in the smaller Martini Room. Fashionable dress is required.

Friday
Apex -- Friday's only 18-and-over gay dance night features high-energy dance music in the main room, with karaoke upstairs and a rotating team of VJs spinning videos in the basement.

Cubik -- Simply the biggest and best dance night for fans of electronic dance music, Cubik (formerly known as Buzz) welcomes international DJs on the level of Paul Oakenfold, Bad Boy Bill, Tiesto and Fatboy Slim to Nation. It's a rave-style event, with lots of younger -- and we mean mostly under-25 -- people dancing and having a good time indoors and on the large patio. Dress is very casual, and lines can be long, so arrive early. (Admission is generally cheaper before 11.)

Plush Fridays -- The main floor at Platinum is now ruled by hip-hop, with house, techno, HiNRG, trance and Latin in the basement and VIP lounge. Doors open at 10, and there's no admission charge for ladies until 11; men can sign up for the guest list at www.platinumclubdc.com.

Saturday
Beautiful Saturdays -- You'll hear hip-hop and R&B on the main floor at Platinum, with house, hip-hop and trance in the VIP room. Doors open at 10. Sign up for the guest list at www.platinumclubdc.com.

Glow -- Washington's biggest trance night is at Fur, where DJs like Sasha, Deep Dish and Armin van Buuren take to the decks. Doors open at 10, and discount passes are available from www.clubglow.com.

Liquid Ladies -- One of Washington's most popular dance nights for lesbians and their friends finds uptempo dance and party music at Apex.

Velvet Nation -- Largely gay and largely raucous, Velvet attracts famous touring DJs as well as local hotshots. Its biggest annual event is the Madonnarama, a celebration of all things Material Girl. Expect to groove to house, techno and other club music at Nation. Doors open at 10.

Sunday
Lavish -- Home's new college night has Chris Styles of Hot 99.5 playing hip-hop and Top 40, DJs Travieso and Chino supplying salsa, reggaeton, merengue and bachata, and guest DJs spinning house in the basement. Doors open at 10, and women are admitted free until 11.

Tuesday
Spank Me -- An 18-and-over night at MCCXXIII, one of Washington's most uptight lounges? Apparently so. On Tuesday nights, you still have to dress to impress, but there's hip-hop and Top 40 on the main dance floor; house and trance up on the third floor in the B.E.D.-like Spank. (Get free admission before 11 by printing a coupon from http://www.panoramai.com.)